• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.11a
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• pp.79-85
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• 1997

Virtual holography is a methodology of synthesizing apparent three-dimensional images from two-dimensional photographs. Since the input is photographic images of real objects, the degree of realism exceeds that offered by any computer-aided design software. The three-dimensional appearance is given in real-time by images from arbitrary viewing directions. If infinitely many photographs were taken and pasted together, virtual holography would have been trivial. But, the (infinite) storage requirement would prohibit such an attempt.

• Journal of information and communication convergence engineering
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• v.17 no.1
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• pp.60-66
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• 2019

In this paper, we propose a new free-view three-dimensional (3D) computational reconstruction of integral imaging to improve the visual quality of reconstructed 3D images when low-resolution elemental images are used. In a conventional free-view reconstruction, the visual quality of the reconstructed 3D images is insufficient to provide 3D information to applications because of the shift and sum process. In addition, its processing speed is slow. To solve these problems, our proposed method uses a pixel rearrangement technique (PERT) with locally selective elemental images. In general, PERT can reconstruct 3D images with a high visual quality at a fast processing speed. However, PERT cannot provide a free-view reconstruction. Therefore, using our proposed method, free-view reconstructed 3D images with high visual qualities can be generated when low-resolution elemental images are used. To show the feasibility of our proposed method, we applied it to optical experiments.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.4
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• pp.343-350
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• 1997

Diagnosis of maxillofacial lesions is very difficult. Recent developments in computed tomography enable the production of three dimnesional images of complex anatomical structures from a series of conventional computed tomographic sections. Methods of three-dimensional analysis of computed tomographic images have recently been described. Mostly, reports have concentrated on applications relative to congenital deformities. In this report, one method of three dimensional reformatting is reviwes. Images formed by this method have solid surface appearance and can be color enhanced and manipulated to isolate anatomic structures of interest. The program allows tissue densitis, volumes, and distances. This report emphasizes maxillofacial applications other than those previously reported in the surgical and radiological literature.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.211-216
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• 2005

High-density directional display provides natural three-dimensional images. A large number of directional images are displayed in different horizontal directions with directional rays. There are two different types of display configurations. One is the projection-type and the other is the thin-type. The 64-directional and 128-directional displays using the projection-type configuration and the 72-directional display using the thin-type configuration are presented. The human responses are also shown.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1250-1253
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• 2009

Integral imaging provides an efficient way to display three-dimensional images with high degree of viewing freedom. Pickup process of integral imaging can also be utilized to acquire three-dimensional contents for displays. This paper introduces basic principle and recent progress of integral imaging technique.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.181-190
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• 2006

In the industry, three-dimensional coloring has been needed for a realistic prototype. The Z-corporation developed a 3D printer which provides a three-dimensional colored prototype. However, the process cannot be adopted to models fabricated by other rapid prototyping processes. In addition, time and cost for manufacturing colored prototypes still remain to be improved. In this study, a new coloring process using an ink-jet head is proposed for color printing on a three-dimensional surface. Process parameters such as the angle and the distance between the ink-jet nozzle and the three-dimensional surface should be investigated through experiments. In order to minimize the distortion of a 2D image, the correction matrix according to the sloped angle is proposed and obtained by analysis of printing errors. An image on the doubly curved surface is printed so as to verify the proposed method. As a practical example, a helmet is chosen for printing images on the curved surface. The practical applicability of the correction matrix is then demonstrated by printing the character images on the surface of the helmet.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.131-134
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• 1995

A three dimensional fractal coding with a perceptually enhanced matching is proposed. Since most of medical images (e.g. computed tomography or magnetic resonance image) have three dimensional character, the searching region is extended to adjacent slices. For perceptually enhanced matching, a high frequency booster filter is used for prefiltering of the original image, and the least mean square error matching is applied to this edge enhanced image rather than the original image. From the simulation with the magnetic resonance images ($255{\times}255$, 8bits/pixel). the proposed algorithm provides excellent image quality with compression rations higher than 10. Compared to existing fractal coding the algorithm also provides better subjective image quality with higher compression ratio.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.36-40
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• 2005

Integral imaging is an attractive three-dimensional display technique providing full-parallax full-color three-dimensional images in real-time without any viewing aids. In this paper, we present the recent progress on the three-dimensional display based on integral imaging focusing on its depth and viewing angle enhancement and the three-dimension/twodimension convertibility.

• Imaging Science in Dentistry
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• v.50 no.4
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• pp.373-376
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• 2020

This report presents a rare case of ameloblastoma with histopathologic and radiographic calcification, including 3-dimensional cone-beam computed tomographic (CBCT) images. A 22-year-old woman had hard swelling on the right mandible. Panoramic and CBCT images showed multilocular radiolucencies with internal calcification foci in the right mandible. Three-dimensional images clearly showed varying-sized radiopacities within the lesion from various angles. A histopathologic examination showed central squamous differentiation and more densely packed peripheral palisading ameloblastic cells. Many areas of keratin pearls and calcifications were also seen. Four previous reports have described 5 cases of ameloblastoma showing histopathologic calcification. This might be the first report to present the calcification of ameloblastoma on panoramic and CBCT images, especially on 3-dimensional images.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1755-1760
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• 2004

The holographic velocimetry system has a significant potential for the measurements of three dimensional velocities of particles. In this study, orthogonal two-side holography system was developed to obtain three dimensional velocities and sizes of spray droplets. To get high quality of reconstructed images, singe-exposure holography at two time moments and two orthogonal sides was adopted instead of multi-exposure, single-side holography. From three dimensional positions of droplets determined by reconstruction and image processing system, the three dimensional velocities and sizes of each droplet was extracted using the PTV algorithm. To determine the position of particles in the optical axis, a new focusing parameter was introduced based on the correlation between two droplet images at the same distance. The measured results by holography system were compared with those by the PDPA.